hhs pandemic influenza preparedness planning julie louise gerberding md mph the burden of 250 000 to 500 deaths globally yr 36 and 200 hospitalizations in us 37 5 billion economic costs related pneumonia ever present threat seasonal pandemics happen h1 h3 h2 h7 h5 h9 1918 spanish flu h1n1 1957 asian h2n2 1968 hong kong h3n2 1980 1997 1915 avian 2003 2004 1977 1996 2002 1925 1935 1945 1955 1965 1975 1985 1995 2005 1998 1999 h5n1 severe vietnam hien tt et al new england j med 350 1179 1188 direct human infection virus reservoir strain emergence reassortment a viruses other mammals reassorted addressing local practices situation report 9 widespread spreading prevalence migratory birds broad host range continued outbreaks among domestic poultry mammalian cats pigs etc lethal is evolving sporadic cases 140 reports date most
